November 2014 | Volume 144, No. 5

Cover image

Cover picture: The cone photoreceptor synaptic terminal was modeled as a 3-D lattice of vesicle sites separated by 45 nm and populated with vesicles (2,234 vesicles/μm3) that move with a diffusion coefficient of 0.11 μm2/s. Consistent with experimental data, calmodulin accelerates vesicle replenishment by acting on ribbon sites (red) to enhance the probability that colliding vesicles will attach to the ribbon (see research article by Van Hook et al., 357–378).